Dial in your cool weather kit.

One reason that it’s more difficult to get out and ride during the winter months is that it’s more difficult for your body to maintain an ideal temperature. This increases fatigue and makes riding more strenuous. The Gore bike Wear Functional thermo Base Layer helps your body maintain that temperature more efficiently to make the miles slide by more easily.

The key performance function of the Thermo Base Layer is moisture management. Your body has a much more difficult time regulating its temperature when your skin is wet. The Thermo Base Layer fits like a second skin to increase moisture-management efficiency. The combination of an internal hydrophobic fabric (100% polyester)with an external hydrophilic fabric (100% polyester) pulls moisture away from your body to keep your skin dry and aid in temperature regulation.

Gore designed the Thermo Base Layer with as few seams as possible, since they cause irritation. Where seams were necessary it used flatlock seams, which cause less chafing than the traditional variety. Finally, Gore designed the WS Thermo with an extra long back to give you full coverage in the seated position.

The Gore Bike Wear Functional Thermo Base Layer comes in White or Black. It’s available in sizes Small to XX-Large.

Extra-long back won't expose your backside when you're hunched deep in the drops

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Warm enough for comfort

Familiarity: I've put it through the wringer

Fit: True to size

Size Bought: Small

Bought this for my winter cycling, and now I can't get enough of it! I've worn in on campus and back country snowshoeing and it's never let me down yet. I've used it in temps ranging from -15 to 40, and it's never been too much or too little. Length is generous in the arms and torso, but I never worry about it riding up on my back while I'm hunched down in the drops or out on the trail. I have a small-to-medium athletic body type, with a longer than average reach, too. Another aspect I'm satisfied with is that I never have to worry about getting soaked with my sweat, it does a first rate job dealing with body moisture.

Comment on Bob Gabbitas's review:

Warm Base Layer

Familiarity: I've used it once or twice and have initial impressions

Size Bought: XL

Regarding size, I have a 41" chest, weigh 165 lbs., and am 6'0 tall. The XL is just right, very snug, without being tight. The length is generous, and the arms are generous, probably at least an inch and a half extra in the wrist.

Functionally, I only wore it once, on the lakefront in Chicago, as a base layer, temps around 38 and pretty chilly winds, under several other layers. Seemed to do the job. I had a Smartwool Micro Fleece over it, and the both of them seemed to be damper than I would have expected after riding. I think the Gore would perform better with another synthetic over it, then a Merino Wool over them both. After one ride, not able to really comment on its moisture-wicking properties. Very comfortable against the skin.